IS 3017

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( Reaffirmed 1995 )

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IS:3017 1985

Indian Standard

SPECIFICATION FOR

THERMOSTATS FOR USE WITH

ELECTRIC WATER HEATERS

Fi rst Rev i si on )

Electrical Appliances Sectional Committee ETDC 43

Chairman

SHRI A. N. GROSH

Members

Representing

Development Commissioner, Small Scale Industries

( Ministry of Industry ), New Delhi

SRRI A. BANDOPADHYA ( Alternate to

Shri A. N. Ghosh )

SHRI G. K. AITHAL

Bajaj Electricals Ltd. Bombay

BRIG M. L. ANAND

Consumer Council of India, New Delhi

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IS: 3017 1985

( Continued frompuge

1 )

Mmnbars

SHRI V. K. KAPUR

Repres ing

Director of Industries, Delhi Administration, New

Delhi

SHRI O.P.

SA~HDE~A Alternate)

SHRI G.

L. KESWANI Directorate General of Technical Development,

New Delhi

SRRI KULXOHAN SINQH

Director of Industries, Government of Haryana,

Chandigarh

SHRI

0.

P. BEHL (

Alternate )

SRRI

G.

D. PATIL

Elpro International Ltd, Pune

SERI

H. L. DHAM ( Alternote )

SERI RAJINDER NATH

C. La1 Electricals Mechanicals, Ambala

Sam SATISH CHANDER ( Alternate )

SIIRI

K. P. SETHI

Racold Appliances Pvt Ltd, Pune

SHRI V. K. MANCHANDA ( Alternate )

SHRI

R. N.

SOPdAI

Rallis India Ltd, Bombay

SRRI V. R. DARSHINAMURTHY ( Ahwnatc )

SHRI T. SOMASUNDARAM Department of Industries and Commerce,

SHRI M. RAJAQOPALAN (

kltcmatc)

Government of Tamil Nadu, Madras

RID. SUDHAKAR REDDY

Tamil Nadu Electrical Appliances Manufacturers’

Association, Madras

DR R. RAMARATHANAI~ ( Altcrnatc )

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IS:3017 1985

Indian Standard

SPECIFICATION FOR

THERMOSTATS FOR USE WITH

ELECTRIC WATER HEATERS

Fi rst Rev i si on )

0. FOREWORD

0.1 This Indian Standard ( First Revision ) was adopted by the Indian

Standards Institution on 28 August 1985, after the draft finalized by the

Electrical Appliances Sectional Committee had been approved by the

Electrotechnical Division Council.

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IS:3017 -1985

provisions of the clause apply ) or not applicable and the sub-clauses or

portions thereof which are not applicable are indicated as under:

a) In case of a clause where it is applicable or not applicable, the

wording used is

“This clause of IS : 30 1979* is applicable/not

applicable”.

b) In case of a sub-clause or part thereof ‘Not applicable’.

Wherever a sub-clause of IS : 302-1979* is to be replaced by a new

text, it has been indicated as under:

‘Replacement - followed by the new text’.

Any addition to the existing provisions of a sub-clause of

IS : 302-1979* has been indicated as under:

‘Addition - followed by the text of the additional matter’.

Clauses/tables which are additional to those of IS : 302-1979” are

numbered starting from 101 and additional sub-clauses are numbered

with the main clauses number followed by 101, 102, etc, for example

7.101.

Additional appendices have been numbered starting from AA.

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IS : 3017 - 1985

1. SCOPE

This

clause

of IS

: 302-1979*

is applicable except as follows:

1.1 Replacement

This standard covers the general, safety and performance require-

ments of thermostats of the stem type for use with electric immersion

water heaters electric instantaneous water heaters and electric storage

type water heaters intended for use on ac circuits at voltages not

exceeding 250 V and current rating not exceeding

25

A.

1.2

Replacement

The

standard does not cover the thermostats for use with other

electric appliances.

2.

TERMINOLOGY

This clause of IS

:

302-1979” is applicable except as follows:

2.4,2.8,2.9 to 2.11, 2.17 to 2.19,2.21 to 2.25, 2.28, 2.30, 2.31, 2.38

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ES:3017 1985

2.108 Differential -

The difference between the temperature at which

the “contacts open and the temperature at which they close under the

specified conditions of test.

2.169 Indicated Temperature

- The temperature indicated by the

knob or pointer on the scale of an adjustable or pre-set thermostat or the

temperature marked on a non-adjustable thermostat.

3. GENERAL REQUIREMENT

This clause of IS

: 302-1979*

is

applicable except as follows:

3.1 Para 2 not applicable.

4. GENERAL NOTES ON TESTS

This clause of IS : 302-1979’ is applicable except as follows:

4.1 Notes 3 to 5 not applicable.

4.2 Addition

The water immersion test ( 15.2.4 ) shall be carried out on two

additional samples.

4.7 to 4.9 and 4.12 to 4.14 not applicable.

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IS : 3017 - 1985

NOTE 5 -

For the purposes of this standard, unenclosed thermostats are considered

to be ordinary thermostats. It is. however, understood that a higher degree of

protection against moisture may be obtained when the themostat is mounted in the

appliance.

6.1 c) According to the temperature differential

1) Class 1 - Thermostats having temperature differential not

exceeding 5X,

2) Class 2 -

Thermostats having temperature differential exceeding

5°C but not exceeding 10°C.

7.

MARKING

This clause of IS : 302-1979* is applicable except as follows:

7.1 Replacement

The following information shall be marked on the outer visible

surface

stat:

a)

b)

c)

or on a label firmly attached to the switch head of the thermo-

Name or registered trade-mark of the manufacturer;

Type number, model number and serial number, if any;

Rated voltage in volts and current in amperes;

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IS:3011 - 1985

9. STARTING OF MOTOR OPERATED APPLIANCES

This clause of IS : 302-1979* is not applicable.

16.

INPUT AND CURRENT

This clause of IS : 302-1979: is not applicable.

11. TEMPERATURE-RISE

This clause of IS : 302-1979* is applicable except as follows:

11.2

Replacement

The thermostat is set at its highest setting and is mounted in a

suitable enclosure so that the temperature of the stem differs from the

temperature set on the thermostat by 5 f 1°C and the contacts are in

the closed position but as near the point of opening as possible.

11.4 to 11.6 not applicable.

11.7 Replacement

The thermostat is operated at the rated voltage and rated current

till the steady state conditions are established.

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14.RADIO AND TELEVISION INTERFERENCE

This clause of IS

:

302-1979” is not applicable.

15.

MOISTURE RESISTANCE

IS

:

3017 - 1985

SUPPRESSION

This clause of IS

:

302-1979” is applicable except as follows:

15.2.1 to 15.2.3 not applicable.

15.2.4 Replacement

This test is carried out on the two additional samples of thermostats.

The thermostat is immersed in water up to the stem length at a

temperature of 27 5 2°C.

After i. hour of immersion, the thermostat is removed from water

and dried, care being taken to ensure that all the moisture is removed

from the insulation in the vicinity of the terminals.

The leakage current

is then measured as described in 16.2.

The leakage current shall not

exceed the value specified in 13.2.

The treatment described above and the measurement of the leakage

current are made five times after whioh the sample shall withstand the

electric strength test as specified in 16.4, the test voltage being reduced to

1 000 V.

15.3 Not applicable.

16. INSULATION RESISTANCE AND ELECTRIC STRENGTH

AFTER HUMIDITY TREATMENT )

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The test voltage is 1.06 times the rated voltage, or 1.06 times the

upper limit of the rated voltage range for appliances for dc only, for

single-phase appliances and for three-phase appliances which are also

suitable for single-phase supply, if the rated voltage or the

upper

limit

of the rated voltage range does not exceed 250 V.

The leakage current measured after the application of the test

voltage shall not exceed the value given in 13.2.


16.4 Para

1 Replacement

Immediately after the test given in 16.2, the insulation is subjected

for 1 minute to a voltage of substantially sine-wave form having a

frequency of 50 or 60 Hz.

The value of the test voltage and the points

of application are shown in the following table.

17.

OVERLOAD PROTECTION

This clause of IS : 302-1979* is not applicable.

18. ENDURANCE

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IS: 3017 -1985

19.

20.

21.

22.

not

ABNORMAL OPERATION

This clause of IS

: 302-19?9*

is not applicable.

STABILITY AND MECHANICAL HAZARDS

This clause of IS

:

302-1979” is not applicable.

MECHANICAL STRENGTH

This clause of IS

:

302-1979* is applicable.

CONSTRUCTION

This clause of IS

: 302-1979*

is applicable except as follows:

22.4, 22.9 to 22.12, 22.15 to 22.18, 22.20, 22.23 to 22.30 and

applicable.

22.32

Additional sub-clauses

22.101

Provision for Attaching to Appliances -

A spring clip-to-

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IS : 3617 - 1985

24. COMPONENTS

This clause of IS

:

3021979* is applicable except as follows:

24.2 and 24.4 to 24.10 not applicable.

25. SUPPLY CONNECTIONS AND EXTERNAL FLEXIBLE

CABLES AND CORDS

This clause of IS : 302-1979” is applicable except as follows:

25.3 to 25.14 not applicable.

26. TERMINALS FOR EXTERNAL CONDUCTORS

This clause of IS : 302-1979* is applicable.

27. PROVISION FOR EARTHING

This clause of IS : 3021979* is applicable except as follows:


27.5 Para 1 Replacement

The earth resistance shall be less than 0’1 ohm:

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IS I 3017 - 1985

33. FINISH

This clause of IS

:

302-1979* is applicable except

as

follows:

33.1

Replacement

The .external finish used on metal components shall be of a heat and

moisture resisting nature and shall not be adversely affected by variations

in temperature under normal operating conditions or

during the

endurance test.


Additional clauses

101. DIMENSIONS

101.1 To facilitate interchangeability between different makes, the

preferred dimensions ( see Fig. 101 ) should be as given in 101.2 to 101.4

( see also 0.4 ).

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101.2 Stem - The nominal stem length if measured from the tip of

the switch head shall be 175,275 or 450 mm. The outer diameter of

the stem shall be 8 mm. The stem shall be uniform in diameter and

straight so that it passes freely into a full length gauge of 8.5 mm internal

diameter.

101.3 Switch Head

101.3.1 The height of the switch head including any projections, shall

not exceed 50 mm.

101.3.2 For rectangular type switch heads, the length and breadth

shall not exceed 55 mm and 40 mm respectively. The horizontal

distance between the centre of the stem and any point of the switch head

including terminal projection shall not exceed 50 mm.

101.3.3 For circular type switch heads, the diameter shall not exceed

55 mm including terminal projections, if any.

101.4 Spring Clip - The spring clip shall be designed to clip firmly

over a collar of 25 mm diameter.

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IS : 3017 -

1985

104.1 Type Tests -

The tests specified in Table 101 shall constitute the

type tests and shall be carried out on two samples of thermostats of the

same type and rating selected preferably at random from a regular

production lot. Before commencement of the tests, the thermostats

shall be visually examined and inspected for obvious visual defects

in respect of components, parts and their assembly construction, stability

markings, provision of suitable terminals for supply connection, earthing

and the effectiveness of screws and connections.

The external surface

finish shall be even and free from finishing defects.

TABLE 101 SCHEDULE OF TYl’E TESTS

SL

TEST

No.

1) 2)

i) Protection against electric shock

ii) Temperature-rise

CLAUDE: RETERPXO

3)

8

11

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104.1.1

Criteria of Acceptance -

Both samples shall successfully pass all

the type tests for proving conformity with the requirements of the

standard.

If any of the samples fails in any of the type tests, the testing

authority, at its discretion may call for fresh samples not exceeding

twice the original number and subject them again to all tests or to the

test(s) in which failure(s) occurred.

No failure shall be permitted in the

repeat test(s).

104.2 Acceptance Tests - The following

shall constitute the

acceptance tests:

.

Test

a>

b)

4

Protection against electric shock

Temperature-rise

Insulation resistance and electric strength at

operating temperature

Moisture resistance

Insulation resistance and electric strength

( after humidity treatment )

Clause Reference

8

11

13

4

4

15

16

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18:3017 1985

APPENDIX A

TABLES OF TYPE TESTS

This Appendix of IS : 302-1979* is not applicable.

APPENDIX B

( Clawe 104.2.1 )

SAMPLING PROCEDURE FOR ACCEPTANCE TESTS

This Appendix of IS : 302-1979’ is applicable as indicated in 104.2.1.

APPENDIX C

ELECTRONIC CIRCUITS

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IS: 3017 1985

APPENDIX G

THERMAL CONTROLS AND OVERLOAD RELEASES

This Appendix of IS

:

302-1979* is not applicable.

APPENDIX H

MEASUREMENT OF CREEPAGE DISTANCES AND

CLEARANCES

This Appendix of IS : 302-1979* is applicable.

APPENDIX J

TEST FOR FIRE-RESISTING PROPERTIES

This Appendix of IS

:

3OL-1979* is applicable.

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IS : 3017 - 1985

APPENDIX AA

Clauses 103.1

and

18 )

METHOD OF DETERMINING OPERATING TEMPERATURE

AND DIFFERENTIAL OF THERMOSTATS

AA-l. GENERAL

AA-l.1 Test

Tank -

A test tank fitted with a horizontal pocket

on

one side into which the thermostat can be fitted to its full length shall

be used.

The pocket shall be of copper with an internal diameter o

8.5 mm and a wall thickness of 0.710 mm. The tank is filled with water

to a level 10 mm above the top level of the pocket.

A mercury-in-glass

thermometer is used to read the temperature of the water. Arrange-

ments are made for the uniform heating and cooling of the water-bath.

The ambient temperature of the room shall be 27 f 5°C.

AA-2. PROCEDURE

AA-2.1 Adjustable thermostats are tested with their controls set at 70°C

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IS:3017 - 1985

AA-2.2

The temperature of the water-bath shall be brought to 15°C

below the setting of the thermostat or its indicated temperature and

maintained at that level for one hour with the heating load connected

to the thermostat switched off by the control switch. At the end of one

hour, the temperature of the bath is uniformly raised at a rate not

exceeding 15°C per hour and the control switch is switched on, passing

the rated current through the contacts of the thermostat. The tempe-

rature of the water at the moment when the contacts open ( as indicated

by the test lamp ) is noted as the operating temperature ( cut-out

temperature ).

AA-2.3

The temperature of the water is then allowed to fall uniformly

at a rate not exceeding 15°C per hour and the temperature of the water

at the moment the contacts close ( as indicated by the test lamp ) is

noted as the cut-in temperature.

AA-2.4

The difference between the cut-out and cut-in temperature is the

differential for the thermostat.

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AMENDMENT NO. 1 MARCH I390

TO

IS : 3017 - 1985 SPECIFICATION FOR THERMOSTATS

FOR USE WITH ELECTRIC WATER HEATERS

(

F irst Revision

[ Page 7 , clause 6.1(c)

]

-

Substitute the following for the existing matter

:

‘6.1 (c) According to temperature differential

l)Classl- Thermostats having temperature differential not exceeding 5 SC.

2) Class 2 - Thermostats having temperature differential not

exceeding

10 .*

(ETDC32)

Reprography nit.BIS,New Delh

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ARIENDMEN’I NO. 2 AUGUST 1991

TO

1s 3017 : 1985 SPECIFICATION

FOR THERMO-

STATS FOR USE WITH

ELECTRIC WATER

I 1

EATERS

( Page 13, Fig. 101 ) -- Substitue the following li,r the existing

figure:

-

I

SWITCH

HE AO_

I

SWITCH

HEAD

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AMENDMENT NO. 3 MAY 1992

TO

IS 3017 : 1985 SPECIFICATION FOR THERMOSTATS

FORUSE WITH ELECTRIC WATER HEATERS

First Revbion )

Substitute ‘IS 302-l(1979) Safety of household and similar electrical

appliances: Part 1 General requirements (

f i ft h revi si on )’ for ‘I S

302

:

1979

General and safety requirements for household and similar electrical appliances

f i f th evis ion’

wherever it appears in the standard.

(ETD32)

Reprography Unit, BIS, New Delhi, India

Documents

IS 3017